1993 hyundai cuts out while driving.... imfrustrated... plz

I have a 1993 hyundai.... it cuts out while driving and while idling... I brought it to me hyundai dealer he said a need a sensor . The idling seems togo very low when stopped and therefore stops. Today i barely made it home it was cutting out on me... no power and when i press the gas it doesnt want to go just a little at a time. I finally made it home. Can the idling sensor do that? I guess its called a servo kit! Thats what my huyundai dealer said.5